This invention relates to a bearing asssembly,
Some bearing assemblies, for example those used in suspension systems of road and rail vehicles, are required to accommodate relatively large movements while at the same time being subjected to relatively low amplitude movements at high frequency, for example oscillations of .+-.2.degree. at a frequency of 30 Hz.
Elastomeric bearings have been used in these circumstances, but a large bulk of elastomeric material is required in these bearings to provide the required range of movement without causing excessive radial and shear stresses in the material. This means that an elastomeric bearing is likely to be large and heavy, with high material costs.
Self-lubricating bearings have also been used. While these can be smaller than the equivalent elastomeric bearing, the low amplitude high frequency movements cause significant wear in the bearing material, and frequent replacement of the bearings is necessary. Thus, although a self-lubricating bearing can accommodate the required range of movements and can withstand high forces, its service life is often too short. For example, when used in a vehicle, replacement of the bearing may be necessary after 30,000 miles of vehicle operation.